A Formal Approach to Grammaticalization:Taking English auxiliary do for example

Grammaticalization,a popular topic in the study of functional linguistics,has long been deemed as a way,motivated by function or experience,of creating grammar.Such a view poses a serious challenge to the claim of formal linguistics that language is an autonomous system.This paper,taking English auxiliary do for example,discusses the phenomenon of grammaticalization from a formal approach,attempting to show that grammaticalization belongs to the parametric category of particular languages and that it is just a process of lexical reanalysis caused by the change of morphophonological realization of functional features.It is argued that the process of grammaticalization,affected by the built-in conservative nature of the learner,involves structural simplification,and that the change of the structure is prior to the relevant semantic change and independent from other systems.The result shows that the formal approach is more expressive in accounting for the mechanism of grammaticalization and can explain the nature of grammar more effectively.